Tags: Chemical Substance, Mineral.
Dimorphite (chemical name tetraarsenic trisulfide) is a very rare orange-yellow chalcogenide mineral. In nature dimorphite forms primarily by deposition in volcanic fumaroles at temperatures of 70–80 °C (158–176 °F). Dimorphite was first discovered in a such a fumarole near Naples Italy in 1849 by the mineralologist Arcangelo Scacchi (1810–1893). Since its discovery dimorphite has been found in the Alacrán silver mine near Copiapó Chile.